1. Field of the Invention
The present invention relates to a cell set capacity controlling system and a cell set capacity controlling method.
2. Description of the Related Art
Recent years have observed developments of electric vehicles and hybrid vehicles that have mounted thereon, as a drive power source, a cell set comprised of a set of simplex cells connected in series. The cell set is provided with a cell set capacity controlling system for a capacity adjustment thereof to prevent excessive charge or discharge of individual cells.
Japanese Patent Application Laying-Open Publication No. 2004-31012 has proposed a cell set capacity controlling system, which detects an SOC (state of charge) of a respective cell, determining an average SOC of whole cells, and judges if the average SOC resides within a range of SOC in which a specified cell open-circuit voltage Vo vs. SOC characteristic curve has an inclination (ΔVo/ΔSOC) greater than a prescribed value. If the average SOC resides in this SOC range, individual cells of the cell set are SOC-controlled in accordance with an SOC control time and discharge capacity determined as capacity control conditions for a respective cell.